#ifndef _EXDLL_H_
#define _EXDLL_H_





//
// only include this file from one place in your DLL.
// (it is all static, if you use it in two places it will fail)
//
#define EXDLL_INIT()           {  \
        g_stringsize	= string_size; \
        g_stacktop		= stacktop;      \
        g_variables		= variables; }




//
// For page showing plug-ins
//
#define WM_NOTIFY_OUTER_NEXT (WM_USER+0x8)
#define WM_NOTIFY_CUSTOM_READY (WM_USER+0xd)
#define NOTIFY_BYE_BYE 'x'

typedef struct _stack_t 
{
  struct _stack_t	*next;
  char				text[1]; // this should be the length of string_size
} stack_t;


static unsigned int		g_stringsize;
static stack_t			**g_stacktop;
static char				*g_variables;

enum
{
INST_0,         // $0
INST_1,         // $1
INST_2,         // $2
INST_3,         // $3
INST_4,         // $4
INST_5,         // $5
INST_6,         // $6
INST_7,         // $7
INST_8,         // $8
INST_9,         // $9
INST_R0,        // $R0
INST_R1,        // $R1
INST_R2,        // $R2
INST_R3,        // $R3
INST_R4,        // $R4
INST_R5,        // $R5
INST_R6,        // $R6
INST_R7,        // $R7
INST_R8,        // $R8
INST_R9,        // $R9
INST_CMDLINE,   // $CMDLINE
INST_INSTDIR,   // $INSTDIR
INST_OUTDIR,    // $OUTDIR
INST_EXEDIR,    // $EXEDIR
INST_LANG,      // $LANGUAGE
__INST_LAST
};





//
// utility functions (not required but often useful)
//
static int popstring( char *str )
{
  stack_t	*th;


  if( !g_stacktop || 
	  !*g_stacktop )
	  return 1;

  th			= (*g_stacktop);
  lstrcpy( str, th->text );
  *g_stacktop	= th->next;
  GlobalFree( (HGLOBAL)th );

  return 0;
}




static void pushstring( char *str )
{
  stack_t	*th;


  if( !g_stacktop )
	  return;

  th			= (stack_t*)GlobalAlloc( GPTR, sizeof(stack_t) + g_stringsize );
  lstrcpyn( th->text, str, g_stringsize );
  th->next		= *g_stacktop;
  *g_stacktop	= th;
}





static char *getuservariable( int varnum )
{
  if( varnum < 0 || 
	  varnum >= __INST_LAST )
	  return NULL;

  return (g_variables + varnum*g_stringsize);
}





static void setuservariable( int varnum, char *var )
{
	if( var != NULL && 
		varnum >= 0 && 
		varnum < __INST_LAST ) 
		lstrcpy( g_variables + varnum*g_stringsize, var );
}



#endif//_EXDLL_H_